from manim import *

# manim --save_sections -p -ql section_demo.py MySectionDemo
class MySection(Scene):
    def construct(self):
        square = Square(color=BLUE, fill_opacity=0.5)
        self.play(Create(mobject=square))

        self.next_section(name="transform to circle")
        circle = Circle(color=GREEN, fill_opacity=0.5)
        self.play(Transform(mobject=square, target_mobject=circle))

        self.next_section(name="fade out")
        self.play(FadeOut(square))